1. Field of the Invention
This invention relates to light-emitting structures for optical devices such as cathode-ray tube ("CRT") displays of the flat-panel type. More particularly, this invention relates to light-emitting structures in which certain portions produce light when struck by electrons and in which other portions, conventionally referred to as "black matrices" are substantially non-emissive of light when struck by electrons. This invention also relates to the manufacture of light-emitting structures containing black matrices.
2. Description of Related Art
A flat-panel CRT display contains a transparent faceplate, a backplate (sometimes referred to as a baseplate), and connecting walls situated outside the active picture area to form a sealed enclosure. The CRT display is typically maintain at a very low internal pressure. An array of laterally separated sets of cathodic electron-emissive elements are situated along the interior surface of the backplate. A phosphor coating, typically divided into an array of separate phosphor regions, is situated along the interior surface of the faceplate.
During display operation, the electron-emissive elements are selectively excited to cause certain of the elements to emit electrons that move towards phosphors on the faceplate. These phosphors, upon being struck by the impinging electrons, emit light that is visible at the exterior surface of the faceplate.
The electrons emitted from each of the sets of electron-emissive elements are intended to strike only certain target phosphors. However, some of the emitted electrons invariably strike portions of the faceplate outside the target phosphors. To improve contrast at the faceplate, a matrix of dark non-reflective regions that emit substantially no light when struck by electrons from the electron-emissive elements are suitably dispersed among the phosphor regions. In a color display, this black matrix also improves color purity. The phosphor regions extend further away from the faceplate than the black matrix.
In a flat-panel plasma display formed with a pair of glass plates, barrier ribs consisting of metal or dielectric material are typically inserted between the plates to maintain a desired inter-plate spacing. Andreadakis et al, "Influence of Barrier Ribs on the Memory Margin of ac Plasma Display Panels," Procs. SID, Vol. 31/4, 1990, presents a study on various configurations for barrier ribs in plasma display panels. Techniques for manufacturing barrier ribs for plasma display panels are described in (a) Fujii et al, "A Sandblasting Process for Fabrication of Color PDP Phosphor Screens,"SID 92 Digest, 1992, pp. 728-731, (b) Terso et al, "Fabrication of Fine Barrier Ribs for Color Plasma Display Panels by Sandblasting, " SID 92 Digest, 1992, pp 724-727, and (c) Kwon, U.S. Pat. No. 5,116,704. Both Fujii et al and Terso et al use sandblasting techniques in forming barrier ribs. Fujii et al also employs sandblasting in fabricating light-emitting phosphor structures for plasma display panels.